Tandem injection molding machine with direct feed to molds

ABSTRACT

An injection molding machine wherein a molding compound supply unit having a nozzle is moveable relative to a plurality of mold stations. Clamps are provided as an adjunct to the supply unit or as an adjunct to the mold stations for effecting a compound seal at each mold station. Appropriate power sources are provided for accomplishing the seal.

BACKGROUND OF THE INVENTION

The present invention relates to injection molding machines having atleast two molding stations arranged in tandem wherein a single moveablenozzle is employed to service each molding station in sequence.

SUMMARY OF THE INVENTION

It is a feature of the present invention to provide a source of moldablecompound including a nozzle means where the nozzle is moveable, while incommunication with the compound source, from station to station tointroduce moldable compound into a mold located at the respectivestations

A further feature of the invention is the provision of mold means havinga parting line wherein the mold means includes a mold inlet means whichis arranged coaxially with at least a portion of the mold parting line.

A further feature of the invention is the provision of a mold inletmeans which is a seamless extension of the mold means.

A still further feature of the invention is the provision of means suchas an extruder or like apparatus for advancing moldable material towarda molding station wherein a nozzle means is carried by supply means andthe supply means and the nozzle means are moveable as a unitary assemblyfrom station to station.

A further feature of the invention is the provision of primary clampingmeans for clamping molds along a longitudinal axis of the moldingmachine and a secondary clamping means for clamping the nozzle meansdirectly to a mold (or to a hot runner manifold servicing a mold) alongan axis that is generally perpendicular to the longitudinal axis.

It is a further feature of the invention wherein the secondary clampingmeans and the nozzle means are both carried by the supply means.

It is a further feature of the invention wherein a secondary clampingmeans is provided at each molding station.

A further feature of the invention is the provision of moveable platendisposed between two mold stations where the platen supports hot runnermanifolds servicing molds at each station, and the platen includessecondary clamping means individual to each manifold for clamping amoveable nozzle to a manifold inlet.

An injection molding machine embracing certain principles of the presentinvention may comprise moveable supply means for introducing moldablematerial into said mold means, nozzle means carried by said supplymeans, power means for moving said supply means operable to registersaid nozzle means with each said mold inlet means, and nozzle clampmeans (secondary clamp means) for sealing the nozzle means to matingmold inlet means.

A process embracing certain other principles of the invention andpracticed by the operation of apparatus of the present invention maycomprise the steps of combining a moldable material supply means, asingle nozzle means and a clamp means into a unitary assembly and movingthe assembly from station to station to seal the nozzle and to supplycompound via said nozzle at each station in sequence.

The language "mold inlet means" includes a seamless extension of a moldor a .[.hOt.]. .Iadd.hot .Iaddend.runner manifold servicing a mold.

Other features and advantages of the present invention will become moreapparent from an examination of the succeeding specification when readin connection with the appended drawings, in which;

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a typical tandem arrangement ofmold stations A and B.

FIG. 2 is a top plan view of the illustration of FIG. 1.

FIG. 3 is a fragmentary view of a portion of FIG. 2, enlarged forclarity.

FIG. 4 is a vertical section of FIG. 3 in the plane of line 4--4 asviewed in the direction of the arrows.

FIG. 5 is a top plane view, partially in section, showing an alternativeembodiment of the present invention.

FIG. 6 is a sectional view of the showing of FIG. 5 as viewed in theplane of the line 6--6 and in the direction of the arrows, and;

FIG. 7 is a sectional view of FIG. 6 as viewed on the plane of line 7--7and in the direction of the arrows.

DETAILED DESCRIPTION OF THE INVENTION

Referring in detail to FIGS. 1, 2, 3 and 4, a typical tandemly arrangedinjection molding machine 11 includes fixed platens 5 and 10, moveableplatens 15 and 20 and two molding stations A and B, each having molds 12and 13 opened, closed and clamped under control of primary clampingmeans (PC) in well known fashion. That is, both molds can be openedseparately or individually and can be clamped separately or in unisondepending upon the manner in which the primary clamping means isprogrammed.

Each mold means has an inlet means 14 and 16 which is an extension ofthe mold body and the inlet means is generally coaxial with the moldparting lines 17 and 18.

The inlet means disclosed is a seamless adjunct to the mold body;obviously the inlet means could be designed as a separate piece partfastened by appropriate means to the mold body.

Molding material is supplied to the mold stations A and B by a moveablemolding material supply means 19, which in the present disclosure, is anextruder 21 having an attached nozzle means 22 and a nozzle valve 23.

The extruder, nozzle means and valves are moveable as an assembly, toand from mold station to mold station under control of a first powermeans P.

As indicated in greater detail in FIGS. 3 and 4, the extruder 21, itsnozzle 22 and valve 23 are moveable into registration with a mold inletmeans such as is illustrated in FIG. 3.

In the arrangement of FIGS. 3 and 4, the moveable assembly includes anozzle clamp means 24 and nozzle clamp power means 26.

The nozzle clamp power means 26, secured to the nozzle means by asuitable fastener such as by bolts 27 and 28, comprises apiston-cylinder assembly supported in a body member .Iadd.29.Iaddend.terminating in a pair of dogs or claws 31 and 32, operable toslide into and make an interlocking connection with mating slots 33 and34 formed in the mold inlet means as is most apparent in FIG. 4.

When the extruder, nozzle, nozzle valve, nozzle clamp and nozzle clamppower means are moved as an assembly and are positioned in register withthe nozzle inlet means as shown in FIG. 3 at Station A, the nozzle clamppower means 26 is energized to place the dogs 31 and 32 under a tensilestress as piston 36 bears down upon the nozzle 22 .[.t ©seal.]. .Iadd.toseal .Iaddend.the nozzle to the inlet means. Upon opening nozzle valve23, moldable material is injected into the mold.

FIGS. 5, 6 and 7 show an alternative arrangement wherein a moveableplaten 37, having opposed hot runner manifolds 38 and 39 supplyingmoldable material to molds at stations A and B, supports nozzle clampmeans 41 and 42 individual to each mold station.

That is, in this arrangement the nozzle clamp means is separate from themolding material supply means and is fixed at each mold station.

Suitable power means such as piston-cylinder assemblies 43 and 44, undercontrol of nozzle clamp control means S₁ C₁ are operable to seal nozzlemeans .Iadd.46 .Iaddend.to respective hot runner manifolds (mold inletmeans) when the extruder 47 is moved into registry with each manifoldinlet.

It is to be understood that the invention is not limited to theillustrations described and shown herein, which are deemed to be merelyillustrative of the best modes of carrying out the invention, and whichare susceptible of modification of form, size, arrangement of parts anddetails of operation. The invention rather is intended to encompass allsuch modifications which are within its spirit and scope as defined bythe claims.

What is claimed is:
 1. In an injection molding machine having a seriesof tandemly arranged molding stations wherein each molding stationincludes a mold having a parting line and a mold inlet,said mold inletdefining a lateral extension of said mold, said parting line extendinginto said mold inlet, the improvement comprising: moveable supply meansfor introducing moldable material into each said mold, nozzle meanscarried by said supply means said nozzle means cooperating with eachsaid mold inlet, power means for moving said supply means operable toregister said nozzle means with each said mold inlet, nozzle clamp meansmoveable along each said parting line for sealing the nozzle means to amating mold inlet, and primary clamp means for sealing said parting lineand said parting line extension along a first axis.
 2. The machine ofclaim 1 wherein the nozzle means defines one nozzle operable to registerwith each mold inlet selectively and individually.
 3. The machine ofclaim 1 wherein the nozzle clamp means is a fixture at each moldingstation.
 4. The machine of claim 1 wherein the nozzle clamp means iscarried by said supply means.
 5. The machine of claim 1 wherein eachmold inlet is disposed generally coaxially with and bisected by saidparting line.
 6. The machine of claim 5 wherein each mold inlet is aseamless extension of the mold.
 7. The machine of claim 4 wherein thenozzle clamp means and an associated mold inlet make an interlockingconnection.
 8. The machine of claim 7 wherein the interlockingconnection defines at least one claw and a cooperating slot.
 9. Themachine of claim 8 wherein the at least one claw is carried by saidnozzle clamp means, and the slot is formed on each said mold inlet. 10.The machine of claim 9 wherein the at least one claw is fixed to saidsupply means and the slot is formed in said mold inlet.
 11. The machineof claim 10 wherein the supply means includes nozzle clamp power meansfor placing the at least one claw and cooperating slot under tensilestress while pressing the nozzle means to a mating mold inlet to createa seal.
 12. The machine of claim 11 wherein the nozzle means includes avalve means operable to seal the nozzle means when the nozzle means isin transit from one molding station to another molding station.
 13. Themolding machine of claim 1 including a secondary clamp means forclamping said nozzle means to a mold inlet wherein the secondary clampmeans clamps along a second axis which is generally perpendicular tosaid first axis.
 14. The machine of claim 2 wherein said nozzle clampmeans includes power means individual to each mold station for pressingthe nozzle means into sealing contact with a corresponding mold inlet.15. In an injection molding machine having a series of tandemly arrangedmolding stations wherein each molding station includes a mold, a moldinlet and a hot runner, the improvement comprising:a single platencommon to a pair of adjacent mold stations, a first hot runnercommunicating with a first mold inlet said first mold inlet disposed onone side of said platen, a second hot runner communicating with a secondmold inlet said second mold inlet disposed on an opposite side of saidplaten, moveable supply means for introducing moldable material intoeach hot runner, a nozzle carried by said supply means said nozzle beingoperable to connect with each hot runner, and first and second nozzleclamps supported by said single platen, said first and second clampsbeing associated with a corresponding molding station for sealing saidnozzle to said first and second hot runners selectively whereby moldablematerial is supplied to each mold inlet individually via respective hotrunners. .Iadd.
 16. In an injection molding machine having a series oftandemly arranged molding stations wherein each molding station includesa mold and a mold inlet, the improvement comprising:moveable supplymeans for introducing moldable material into each said mold, nozzlemeans carried by said supply means, power means for moving said supplymeans operable to register said nozzle means with each said mold inlet,nozzle clamp means for sealing the nozzle means against each mold inlet,and said nozzle clamp means carried by said supply means forms a unitaryassembly together with the nozzle means, said assembly being selectivelypositioned at one of said mold inlets. .Iaddend.